Improvement in screw-cutting devices



STEPHEN NORTH.

Improvement in Screw-Cutting Device.

N0, 125 980, v Patented April23,1872.

STEPHEN NORTH, OF SYRACUSE, NEW YORK.

-|MPROVEMENT IN SCREW-CUTTING DEVICES.

Specification forming part of Letters Patent No. 125,980, dated April 23, 1872.

Specification describing an Improved Screw- Gutting Device, invented by STEPHEN NORTH, of Syracuse, in the county of Onondaga and State of New York.

In attaching glass insulators to telegraph poles the insulators are mounted on tapering brackets, studs, or pins, and are secured firmly to said pins by being screwed on, the glass being cast with a screw-socket and the wooden pin having a thread cut upon it. The thread is out upon the pin in an irregular and imperfect manner, ordinarily, the work being done with a hand-tool while the pin is in the turnin g-lathe, and, owing to the want of uniformity of thread, some of the insulators work loose on the pins and are liable to come off. The invention relates to an improved device for cutting the thread on these tapering-pins, whereby the work is done with perfect uniformity and with a saving of labor; and the invention consists in a tool that to some extent may be compared to a screw-plate, but the dies are suspended on pivots and pressed against the work by rubber or other elastic supports; and while the dies only feed the work to the cutter, the cutting is done by a small gouge or wood-tool that is secured to one of the dies in a detachable manner, as hereinafter more fully explained.

Figure 1 is an edge or side view, and Fig. 2 is a front view of my invention. Fig. 3 shows one of the wooden pins or studs.

Similar letters of reference indicate like parts in the separate figures.

A is a face-plate, which is run in a lathe with a forward and backward motion. On

this face-plate the several dies 1) b b are mounted by being pivoted to its collar, a, by the pins d, Fig. 2. Each die has an elastic support or piece of rubber, e, in its rear, and

the said rubber has a bearing in a standard,

B, projecting from the face-plate. The inner face of each die has a screw-thread face, as shown in Fig. 1, to feed the pins into and out of the tool; and one of its dies has a cutter, 0, secured to its side by a plate, 0, and setscrews; and this cutter makes the screw-thread on the pin as it is fed into the tool. The elastic supports 0 e 6 allow the tool to accommodate itself to the varying size of the work. Metallic springs can be substituted in place of the rubber.

By these means the work of cutting a screwthread upon these tapering-pins is done with entire uniformity and with a saving of labor, as the pins have only to be fed to the machine, which can be done by boys or by unskilled labor.

I claim- The combination, with the rotary face-plate A, for use in a lathe, of the standards B B B, the collar to, pivoted dies 11 b b, elastic supports 6 e, and a cutter, c, all constructed, arranged, and operating substantially as herein described.

The above specification of my invention signed by me this Oth day of March, 1872.

STEPHEN NORTH.

Witnesses:

F. A. MoRLEY, H. HAGAR. 

